“It appears a build-up of methane gas caused the explosion, with the flammable fumes generated by a filled septic tank. Methane is a byproduct of waste decomposition, produced by anaerobic bacteria. The toilet, poorly ventilated, had seen a dangerous build-up of the gases. Sitting down on the toilet had caused some of the gas to compress, making it more volatile, and flicking the light switch was then all that was needed to ignite the bowl.”

It adds “most domestic UK toilets would be incapable of replicating the explosive conditions found in the Barcelona toilet, thanks to plumbing and sewerage systems swiftly sending the waste far from a property.” (Phew)

The woman is reported to have launched legal action against the bar for the injuries she sustained.